1. Field of the Invention
The present invention relates generally to a multi-position grip system for a weight machine, barbells or the like which permits a user to perform the multi-axis hand rotation possible with single-handed dumbbells while at the same time achieving the balance and control of two-handed devices such as barbells, pulley bars, and weight machines. More particularly, it is concerned with a grip system having a handgrip and a series of arcuate members concentrically and rotatably coupled to present three rotational axes, which permit continuous multi-axis hand and wrist movement of a user throughout the range of motion in a variety of exercises.
2. Description of the Related Art
In recent years weight lifting has become an increasingly popular form of exercise. Most weight training exercises can be performed using either one-handed dumbbells, consisting of a short bar with weights at either end, or two-handed barbells consisting of a straight bar with weights at both ends.
Since one dumbbell is held in each hand, a user can freely rotate the wrist and hand throughout the full range of motion as an exercise is performed. For example, in performing a shoulder press with dumbbells, a user holds a dumbbell in each hand directly beside the shoulders, with palms facing toward each other. The dumbbells are raised over the head and the palms are rotated to face forward. The palms are rotated back to the starting position as the weights are lowered.
The same exercise can be performed with a barbell by grasping the bar with an overhand grip, straightening up and lifting the weight to shoulder level, then lifting the bar up over the head. Heavier weights can be lifted using the barbell because it permits greater balance and control. However, the hands and wrists must be held in a relatively fixed position, and may be rotated only along the axis of the bar. Thus, it is not possible to use a standard barbell to exercise the groups of muscles involved in pronation and supination as with dumbbells. Moreover, the necessity of maintaining such a fixed position during exercises with the heavier barbell increases strain on the wrists and elbows. In addition, safety is compromised by the inability to reposition grip in the midst of a lift or exercise to obtain better control.
Prior art devices have attempted to impart some wrist rotation to the standard barbell, but do not provide a full range of motion for a user and are generally not adaptable for attachment to a weight or similar exercise machine. U.S. Pat. No. 4,690,400 issued to Metz permits rotation of handles along the same axis as the bar; U.S. Pat. No. 3,384,370 issued to Bailey; U.S. Pat. No. 4,822,035 issued to Jennings; U.S. Pat. No. 5,024,434 issued to Smith; and 33,218 reissued to Twardosz permit rotation of handles on a single axis perpendicular to the rod. U.S. Pat. No. 4,629,184 issued to Selkee permits rotation of handles along a pair of axes.